Hybrid machines or electrically driven machines, being widely spread in place of internal combustion engines, have an electric storage apparatus unit mounted thereon as a power source for a motor. Such an electric storage apparatus unit is provided with electric storage apparatuses in which rechargeable electric storage devices, such as battery cells (lithium ion battery cells, nickel hydrogen battery cells, or the like) and capacitors (electric double layer capacitors, or the like), are packaged in a number corresponding to specification requirements of machines.
For example, a battery pack (electric storage apparatus unit) disclosed in JP 2011-108652 A has a configuration in which battery modules 100 (electric storage apparatuses) each composed of a plurality of unit battery cells 110 (electric storage devices), an upper frame 120, a lower frame 130, side frames 140, and end plates 150, as shown in FIG. 1 of JP 2011-108652 A, are aligned in the up-down direction and width direction, as shown in FIG. 6 thereof.
Further, a power source apparatus (electric storage apparatus unit) disclosed in JP 2012-094456 A has a configuration in which battery stacks 50 (electric storage apparatuses) each composed of a plurality of rectangular battery cells 1 (electric storage devices), binding bars 11, and end plates 4, as shown in FIG. 3 of JP 2012-94456 A, are aligned in the longitudinal direction and lateral direction on a base plate 6, as shown in FIG. 3 and FIG. 2 thereof.
Meanwhile, such an electric storage apparatus unit is installed in a limited space of a machine and thus is required to eliminate waste spaces as much as possible, so as to be downsized.
The battery pack (electric storage apparatus unit) disclosed in JP 2011-108652 A, as seen from such a viewpoint, has waste spaces between adjacent battery modules 100 (electric storage apparatuses) because, when the battery modules 100 (electric storage apparatuses) are transversely aligned, they are required to be spaced from each other so as to prevent the heads of bolts for fixing the side frames 140 to the end plates 150 from abutting each other.
Further, the power source apparatus (electric storage apparatus unit) disclosed in JP 2012-094456 A has waste spaces between adjacent battery stacks 50 (electric storage apparatuses) because, when the battery stacks 50 (electric storage apparatuses) are transversely aligned, they are required to be spaced from each other so as to prevent fixing pieces 31 for fixing the binding bars 11 to the base plate 6 from abutting each other.